Dual specificity protein phosphatase 22 (DUSP22), also called JNK-stimulatory phosphatase-1 (JSP-1), low molecular weight dual specificity phosphatase 2 (LMW-DSP2), mitogen-activated protein kinase phosphatase x (MKP-x) or VHR-related MKPx (VHX), functions as a protein-serine/threonine phosphatase (EC 3.1.3.16) and a protein-tyrosine-phosphatase (EC 3.1.3.48). It deactivates its MAPK substrates by dephosphorylating the threonine and tyrosine residues in the conserved Thr-Xaa-Tyr motif residing in their activation sites. DUSP22 is an atypical DUSP; it contains the catalytic dual specificity phosphatase domain but lacks the N-terminal Cdc25/rhodanese-like domain that is present in typical DUSPs or MKPs. DUSP22 negatively regulates the estrogen receptor-alpha-mediated signaling pathway and the IL6-leukemia inhibitory factor (LIF)-STAT3-mediated signaling pathway. It also regulates cell death by acting as a scaffold protein for the ASK1-MKK7-JNK signal transduction pathway independently of its phosphatase activity.
Jiyao W et al.(2023). "The conserved domain database in 2023.",